1. Field of the Invention
The present invention relates generally to a mill for the production of continuous seam-welded tubes of pipes and, more particularly, to an automated system for changing such a mill from the production of tubes of one size or shape of tube to the production of tubes of another and different size or shape.
2. Description of the Prior Art
In accordance with a well known process for producing seam-welded tubes, a continuous strip or skelp is advanced through forming section of apparatus which includes a series of forming rolls and formed into a tubular form having an open, longitudinally extending seam formed by the abutting edges of strip or skelp being formed. The tubular form is then advanced through a welding section wherein the abutting edges are urged together and joined by a suitable welding process. The welding process may cause the formation of an unwanted bead which may next be removed by a suitable scarfing procedure. The welded tube is then, after passing through a cooling zone, advanced through a series of sizing and squaring rollers whereby the tube is formed to the final configuration and size. The advancing continuous tube is then severed by means of a travelling cutting unit into individual sections of a predetermined length.
The tube forming apparatus is designed to be capable of conversion to the production of various sizes and cross-sectional configurations of tube. As will be readily manifest, such apparatus constitutes massive precision machines representing a considerable investment of capital. Heretofore, it was often necessary to shut down a production of tubes of one size or shape to convert the apparatus to produce tubes of a different size or shape. More specifically, the line was shut down and the various components were individually removed and replaced by components required for production of the next product. The replacement components then had to be properly set and adjusted on the line before production could resume. The entire changeover routine could consume a considerable period of time, as much as five or six hours or more. Obviously, the changeover time involves a considerable expenditure in time and capital, and an extensive loss of production. As a result, it becomes necessary to maintain unduly large inventories of finished products, contrary to the current trend toward maintaining minimum inventory and frequently changing from the production of one product to another.